4 files changed, 60 insertions, 12 deletions

diff --git a/platform/default/mbgl/storage/file_source_request.hpp b/platform/default/mbgl/storage/file_source_request.hpp
new file mode 100644
index 0000000000..6bd0d44df6
--- /dev/null
+++ b/platform/default/mbgl/storage/file_source_request.hpp
@@ -0,0 +1,31 @@
+#pragma once
+
+#include <mbgl/actor/actor_ref.hpp>
+#include <mbgl/storage/file_source.hpp>
+#include <mbgl/util/async_request.hpp>
+
+#include <memory>
+#include <functional>
+
+namespace mbgl {
+
+class Mailbox;
+
+class FileSourceRequest : public AsyncRequest {
+public:
+    FileSourceRequest(FileSource::Callback&& callback);
+    ~FileSourceRequest() final;
+
+    void onCancel(std::function<void()>&& callback);
+    void setResponse(const Response& res);
+
+    ActorRef<FileSourceRequest> actor();
+
+private:
+    FileSource::Callback responseCallback = nullptr;
+    std::function<void()> cancelCallback = nullptr;
+
+    std::shared_ptr<Mailbox> mailbox;
+};
+
+} // namespace mbgl
diff --git a/platform/default/mbgl/storage/offline.cpp b/platform/default/mbgl/storage/offline.cpp
index fd2d47819b..7670790be9 100644
--- a/platform/default/mbgl/storage/offline.cpp
+++ b/platform/default/mbgl/storage/offline.cpp
@@ -1,6 +1,7 @@
 #include <mbgl/storage/offline.hpp>
 #include <mbgl/util/tile_cover.hpp>
 #include <mbgl/util/tileset.hpp>
+#include <mbgl/util/projection.hpp>
 
 #include <rapidjson/document.h>
 #include <rapidjson/stringbuffer.h>
@@ -23,18 +24,12 @@ OfflineTilePyramidRegionDefinition::OfflineTilePyramidRegionDefinition(
     }
 }
 
-std::vector<CanonicalTileID> OfflineTilePyramidRegionDefinition::tileCover(SourceType type, uint16_t tileSize, const Range<uint8_t>& zoomRange) const {
-    double minZ = std::max<double>(util::coveringZoomLevel(minZoom, type, tileSize), zoomRange.min);
-    double maxZ = std::min<double>(util::coveringZoomLevel(maxZoom, type, tileSize), zoomRange.max);
-
-    assert(minZ >= 0);
-    assert(maxZ >= 0);
-    assert(minZ < std::numeric_limits<uint8_t>::max());
-    assert(maxZ < std::numeric_limits<uint8_t>::max());
+std::vector<CanonicalTileID> OfflineTilePyramidRegionDefinition::tileCover(style::SourceType type, uint16_t tileSize, const Range<uint8_t>& zoomRange) const {
+    const Range<uint8_t> clampedZoomRange = coveringZoomRange(type, tileSize, zoomRange);
 
     std::vector<CanonicalTileID> result;
 
-    for (uint8_t z = minZ; z <= maxZ; z++) {
+    for (uint8_t z = clampedZoomRange.min; z <= clampedZoomRange.max; z++) {
         for (const auto& tile : util::tileCover(bounds, z)) {
             result.emplace_back(tile.canonical);
         }
@@ -43,6 +38,28 @@ std::vector<CanonicalTileID> OfflineTilePyramidRegionDefinition::tileCover(Sourc
     return result;
 }
 
+uint64_t OfflineTilePyramidRegionDefinition::tileCount(style::SourceType type, uint16_t tileSize, const Range<uint8_t>& zoomRange) const {
+    
+    const Range<uint8_t> clampedZoomRange = coveringZoomRange(type, tileSize, zoomRange);
+    unsigned long result = 0;;
+    for (uint8_t z = clampedZoomRange.min; z <= clampedZoomRange.max; z++) {
+        result +=  util::tileCount(bounds, z, tileSize);
+    }
+
+    return result;
+}
+
+Range<uint8_t> OfflineTilePyramidRegionDefinition::coveringZoomRange(style::SourceType type, uint16_t tileSize, const Range<uint8_t>& zoomRange) const {
+    double minZ = std::max<double>(util::coveringZoomLevel(minZoom, type, tileSize), zoomRange.min);
+    double maxZ = std::min<double>(util::coveringZoomLevel(maxZoom, type, tileSize), zoomRange.max);
+
+    assert(minZ >= 0);
+    assert(maxZ >= 0);
+    assert(minZ < std::numeric_limits<uint8_t>::max());
+    assert(maxZ < std::numeric_limits<uint8_t>::max());
+    return { static_cast<uint8_t>(minZ), static_cast<uint8_t>(maxZ) };
+}
+
 OfflineRegionDefinition decodeOfflineRegionDefinition(const std::string& region) {
     rapidjson::GenericDocument<rapidjson::UTF8<>, rapidjson::CrtAllocator> doc;
     doc.Parse<0>(region.c_str());
diff --git a/platform/default/mbgl/storage/offline_download.cpp b/platform/default/mbgl/storage/offline_download.cpp
index 7f0001f64b..ff61114888 100644
--- a/platform/default/mbgl/storage/offline_download.cpp
+++ b/platform/default/mbgl/storage/offline_download.cpp
@@ -80,7 +80,7 @@ OfflineRegionStatus OfflineDownload::getStatus() const {
         auto handleTiledSource = [&] (const variant<std::string, Tileset>& urlOrTileset, const uint16_t tileSize) {
             if (urlOrTileset.is<Tileset>()) {
                 result.requiredResourceCount +=
-                    definition.tileCover(type, tileSize, urlOrTileset.get<Tileset>().zoomRange).size();
+                    definition.tileCount(type, tileSize, urlOrTileset.get<Tileset>().zoomRange);
             } else {
                 result.requiredResourceCount += 1;
                 const auto& url = urlOrTileset.get<std::string>();
@@ -90,7 +90,7 @@ OfflineRegionStatus OfflineDownload::getStatus() const {
                     optional<Tileset> tileset = style::conversion::convertJSON<Tileset>(*sourceResponse->data, error);
                     if (tileset) {
                         result.requiredResourceCount +=
-                            definition.tileCover(type, tileSize, (*tileset).zoomRange).size();
+                            definition.tileCount(type, tileSize, (*tileset).zoomRange);
                     }
                 } else {
                     result.requiredResourceCountIsPrecise = false;
diff --git a/platform/default/mbgl/storage/offline_download.hpp b/platform/default/mbgl/storage/offline_download.hpp
index c978ded931..437f221c11 100644
--- a/platform/default/mbgl/storage/offline_download.hpp
+++ b/platform/default/mbgl/storage/offline_download.hpp
@@ -60,7 +60,7 @@ private:
     std::deque<Resource> resourcesRemaining;
 
     void queueResource(Resource);
-    void queueTiles(SourceType, uint16_t tileSize, const Tileset&);
+    void queueTiles(style::SourceType, uint16_t tileSize, const Tileset&);
 };
 
 } // namespace mbgl